Method of winding armatures



March 17, 1953 M. M. HOLE 2,632,124

METHOD OF' WINDING ARMATURES Filed Dec. 29, 1950 TSRQPo/vM/.KHGFED csef-'Fffaaccenxwv /V/QY /W- HOLE `slots being adapted to receive windings.

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Patented Mar. 17, 1953 UNITED `STATSES OFFICE METHOD OF WINDING ARMATURES Mary M. Hole, Dayton, Ohio, assignor to General Motors Corporation, Detroit, Mich., a corporation of Delaware 3 Claims.

This invention relates to an improved armature and the method for producing it.

It is among the objects of the present invention to produce an armature, the windings in which will not ny out or explode when the armature is operated at comparatively high speeds.

A further object of the present invention is to wind an armature in such a manner that the conductors therein will be in substantial balance whenthe armature is rotated.

Further objects and advantages of the present invention will be apparent from the following description, reference being-had to the accompanying drawings, wherein a preferred embodiment of the present invention is clearly shown.

In the drawings:

Fig. l is a diagrammatic view illustrating the cylindrical armature, its slotted body, commutator bars and windings all shown in a iiat plane.

Fig. 2 is an end view of an armature produced in accordance with the present invention.

Fig. 3 is a similar view showing an armature constructed in accordance with standard practlces.

Fig. 4 is an enlarged sectional view ofthe conductor containing, armature slot 4taken at the line 4-4 of Fig. 1.

Fig. 5 is a similar sectional view taken at the line 5-5 of Fig. 1.

The armature of the present invention consists of a shaft upon which is mounted the body portion |2| of the armature and the commutator |22. The body portion 2| is laminated, preferably made up of a plurality of metal discs secured to the shaft l2!) in stacked relation. A plurality of equally spaced radial slots |23 extend throughout the length of the body, the vopen ends of said All slots |23 have an insulating lining |24 of any suitable material. At the open end of each slot there are inwardly extending projections |25 and |26 providing a narrower slot opening in the surface of the armature body than the wire containing por- A wire retaining peg |21, of any suitable insulating material, is inserted longitudinally into each slot, each peg having an enlarged head portion which fits into the wire containing portion of the slot beneath the projections thereof and having also a narrower body portion which fits into the narrower slot space between said two projections. The pegs in the slots are movable longitudinally of the slots but not radially, so Vthat they form locking means preventing the wires from flying out of their respective slots when the armature is rotated, especially at high speeds.

The armature illustrated has 29 slots and 29 ccmniutator bars, the latter being designated 'by the numerals l to 29 respectively. The coils of the armature each have 4 convolutions, one side oi each coil being in one slot while the other side of the coil is in the seventh slot removed, thus providing 7 armature body segments therebetween. By following the heavy line winding A, such spacing may be noted. One end of this winding A is attached to commutator bar while the other is attached to bar I5. Bar connection spacing for the other respective coils of the armature is similar.

Armatures have been produced by various methods, for instance, by introducing preformed 'coils into the body of the armature or by winding the conductor wires directly into the slotted body of the armature. Fig. 3 illustrates the one end of an armature, the windings of which were wound into the body of the armature by the regular method ordinari-ly used. This iigure indicates a group of end loops at area 5| overlapping and lying upon the adjacent groupat area 50. This not only produces unbalance as between the diametrically opposite areas 5-5l! and 52, but also produces an armature subject to explosion especially at high speeds. By explosion it is meant that the unsupported, outside loop portions at the area 5| will loosen and fly outwardly at such high speed armature operation, the loosened winding loops rubbing against the field pieces in which the armature operates and thus causing severe damage tothe electric machine.

Fig, 2 illustrates an armature produced by the improved method of this invention. Here the unbalance of the armature of Fig. 3 is completely eliminated inasmuch as substantial symmetry is maintained among the extending end loops arranged in a circular fashion about the armature shaft. The nal seven end loops marked A to G are carefully folded over and drawn taut to embrace and securely hold adjacent loops therebeneath. These seven loops themselves are sufficiently tight to resist centrifugal force at substantially high armature speeds due to the fact that they come from beneath adjacent loops, are angularly folded over said adjacent loops, and, while drawn tight, placed into their respective slots, locked therein by an inserted peg and then securely attached to their respective commutator bars.

The usual method of winding an armature as illustrated by Fig. 3 is as follows: With one end of the wire secured to the proper commutator bar, the wire is placed in one armature slot, for instance a, then looped around the iront end of the armature placed in the second slot a', then looped around the commutatcr or rear end of the armature and again placed in the said one slot. After the proper number of coil convolutions are placed in the slots, the nal end extending from slot a' is extended toward the armature and then a, locking peg is inserted in slot a. to hold the windings therein. The next adiacent coil is then wound in slots ti-b', the rst end of the wire being secured to its proper corn-v mutator bar and the nal end extending toward the commutator and being temporarily locked in slot b by a peginserted in said slot. Placement of the following coils in slots c-c, d-d, e-e, etc., follows progressively in the same manner. When the position is reached at which the initial end of the coil (for instance AA) is to be placed, the peg, previously placed in slot a', is removed as is also the final lap cr end of the coil already placed therein. Then the coil AA, with its initial end wire secured to its proper commutator bar, is wound into its slots, the rst of which is slot a already containing the wires of coil A. After this coil AA is properly placed in its slots, the removed wire of the rst coil is again placed in slot c' and then the peg is inserted in said slot. This method is followed for the placement of the following six coils BB to GG inclusive. Following this, the extending` ends of all of the coils are secured to their respective commutator bars. By this well known and practiced method, an armature with a rear end as illustrated in Fig. 3 is produced. This method results in the arrangement of windings in slots a' and h as indicated by the Figs. 4 and 5 respectively. Slots a to c have the nal end of the first wound coils therein on top of the other wire or coil ends therein while the remaining slots have their wires superposed in proper sequential order. In Fig. 4, the nal sides of the coils appear superposed in the following manner: Coil A has its nal sides arranged A1, A2 and A3, then coil AA has its final sides arranged AAl, AA2, AA3 and AA4 and then the final side A4 of the rst wound coil is placed on top of the entire group in slot a. In Fig. 5, the sides of the rst coil are placed H1, H2, H3 and H4 and then the second coil is superposed as Q1, Q2, Q3 and Q4 or in sequential order.

The new winding method forming the subject matter of this invention is somewhat like that just described but difiere therefrom when the iinal seven coil-s are to be wound into the armature. Just prior to the placement of coil AA, the iirst of the nal seven coils, all `pegs locking the i-lnal side of coils in slots c to g are completely removed. Then the final coil ends are also removed from said slots d to g and folded back out of the way of subsequent operations. Now the nal seven coils AA to GG inclusive are placed in their respective slots, the first side of said coils being placed in slots a to g respectively. The starting end of these coils AA to GG are, of course, secured to their respective armature bars. After all of the coils AA to GG are placed and their iinal ends extended toward the commutator, the previously removed final sides of coils A to G are again placed in their respective slots a to g and then the locking pegs are inserted in said slots. As these nai coil ends are replaced in their slots, they are carefully placed so that their loop ends at the rear of the armature lap over and embrace adjacent, underneath loops as illustrated in Fig. 2. rThe loose, projecting ends of the several coils are then attached to their respective commutator bars, thus the stretching of the wires and particularly the nal coil sides of the coils A to G, the locking of them in their slots by the pegs and the anchoring of them to their commutator bars all contribute to their ability to hold underneath loops securely and themselves to resist the exploding eiect by centrifugal force when the armature is operated at substantially high speeds.

The important difference between the old method of armature winding herein described and the new method is that, by the old method, each iinal end or side of the first coil is taken from its slot, then the second coil side is Wound therein, immediately after which the removed side of the rst coil is replaced then locked therein by the replaced peg. This follows for each of the succeeding six coils finally placed. By the new method, all of the final sides of the first seven coils are removed from their slots and folded back.. rihen the iinal seven coils are wound, the iirst sides or said coils being placed upon the nal sides of the initially placed coils in slots a to g. After the coils AA to GG are placed, then all of the removed iinal sides or ends of coils A to G are again placed in their respective slots a to g from which they were previously taken and then the locking pegs are inserted in all of the slots a to g. As before stated, the old method produces an armature as illustrated by Fig. 3, while the new method produces the better balanced and more securely locked together armature as illustrated by Fig. 2.

The aforedescribed new method of placing windings in the slots of an armature as schematically depicted by Fig. l of the drawings may be reversed for the sake of assembly conveniences without sacrificing any of the advantages. For instance, the first placed coil may have its leading end attached to commutator ybar 8, then laid into slot a looped over the end of the commutator body and laid into slot h and then looped back to slot a until the required number of convolutions are placed, after which a lock peg would be placed in slot h,` and the trailing end of the coil would extend toward the commutator. The next coil would be attached to bar 9, and would occupy slots g and g. The loops in this particular modekof winding are wound counterclockwise as regards Fig. 1 whereas in the mode of operation as aforedescribed, the coils are wound clockwise. Either way of winding provides the same results as regards the manner of loop fold at the front end of the armature to provide balance and end loop lock against throw out. In this last described modus operandi the treatment of the trailing ends of the first seven placed coils and the placement of the iinal seven placed coils in the particular design is exactly like that given in the iirst described operation.

Thus it may be seen that an armature produced in accordance with the present novel method is in substantial balance and substantially nonexplosive when the armature is operated at high speeds. These advantages are attained without the use of added materials or longer assembling time. A mere change in the winding routine and method vof placement of coil portions without added expense of material or time provide material advantages over the well known and practiced method of armature production.

While the embodiment of the present invention as herein disclosed, constitutes a preferred form, it is to be understood that other forms might be adopted.

What is claimed is as follows:

1. The method of winding an armature consisting of a shaft supporting a cylindrical body portion and a commutator, said body portion having a plurality of radial coil receiving slots extending longitudinally of and spaced equally around said body, said method consisting of the following steps; inserting a loop coil in a pair of predeterminately spaced slots with the leading end of the coil attached to a proper commutator bar, the trailing end extending from its slot toward the commutator; placing a locking peg longitudinally in the slot containing the trailing end of the coil; repeating this coil placement operation progressively around the armature by placement of coils in the predeterminately spaced pair of slots until the leading side of the coil next to be assembled will be placed in the slot containing the trailing end of the first placed coil at which time the peg in this last mentioned slot and the pegs in at least a majority of the slots up to the slot containing the leading convolution of said rst placed coil are withdrawn, following which the respective trailing ends of the coils in the slots from which pegs have been withdrawn are also removed from said slots and bent back out of the way of the subsequent operation; then continuing with the placement of the coils whose leading ends are placed in the slots with pegs removed; then successively taking each bent back coil end, folding it over adjacent coil end loops, replacing it in the slot from which it was previously removed, inserting the peg into each slot after the final coil end has been placed therein, then drawing taut each loose trailing end of a coil extending from the armature body and securing it to the proper commutator bar.

2. A substantially balanced and unexplodable armature having a commutator and a body portion provided with radial slots extending longitudinally of said body portion, a plurality of loop coils placed in said slots, each coil having a leading end attached to a bar of the commutator and a trailing end attached to another bar of the commutator, the trailing and leading side convolutions of each coil being placed in pairs of predeterminately spaced slots in the armature body, each slot containing the leading side convolutions of one coil and on top of them the trailing side convolutions of the second coil, the nal trailing convolutions of the initially placed coils, equal in number to the spacing of the slots occupied by a respective coil, having the leading sides of the finally placed coils superposed thereupon, the last placed trailing convolutions of said initially placed coils being folded over adjacent end loops of previously placed coils and inserted and locked in their respective slots on top of all the coil portions therein, said trailing ends of said initially placed coil convolutions being attached to their respective commutator bars; and a plurality of locking pegs insertable in said slots for securely holding the coil ends in loop supporting positions on the armature body.

3. The method of winding an armature consisting of a shaft supporting a cylindrical body portion and a commutator, said body portion having 29 coil-receiving slots and the commutator a like number of conductor bars, the method consisting of the following steps; securing one end of a single Vwire conductor to a commutator bar then placing four convolutions of said wire conductor in two slots spaced with six slots therebetween and letting the trailing end of the wire extend toward the commutator, placing a holding element in the slot containing the trailing end of the coil, repeating this coil placement operation progressively around the armature until the leading end of the coil next to be placed will occupy the slot already containing the trailing end of the rst placed coil, removing the holding element in this last-mentioned slot and the holding elements in at least four successive slots, then removing the trailing ends of the coils from the slots from which the holding elements have been removed and bending said trailing ends back out of the way to permit placement of the leading ends of coils into said slots from which the said trailing ends have been removed, then successively replacing said bent back trailing coil ends into the slots from which they have previously been removed and inserting locking pegs in said slots, then drawing said trailing, replaced ends taut and folding them over adjacent coil loops and securing the trailing ends of the coils to the proper commutator bars whereby the underneath coil ends are securely held against movement.

MARY M. HOLE.

REFERENCES CITED The following references are of record in the le of this patent:

UNITED STATES PATENTS Number Name Date 1,292,551 Wilson Jan. 28, 1919 1,320,126 Dudley Oct. 28, 1919 1,807,252 Quackenbush May 26, 1931 2,232,773 Daiger Feb. 25, 1941 

